#include <stdio.h>

int main()
{
	char ch;
	ch = getchar();
	if(ch >= 'A' && ch <= 'Z')
	{
		ch += 32;
		putchar(ch);
		putchar('\n');
	}
	else if(ch >= 'a' && ch <= 'z')
	{
		ch -= 32;
		putchar(ch);
		putchar('\n');
	}
	else
		printf("other char");
		putchar('\n');




	return 0;
}
